/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.code.form;

import com.android.dx.dex.code.CstInsn;
import com.android.dx.dex.code.DalvInsn;
import com.android.dx.dex.code.InsnFormat;
import com.android.dx.rop.code.RegisterSpecList;
import com.android.dx.rop.cst.Constant;
import com.android.dx.rop.cst.CstMethodRef;
import com.android.dx.rop.cst.CstType;
import com.android.dx.util.AnnotatedOutput;

/**
 * Instruction format {@code 5rc}. See the instruction format spec for details.
 */
public final class Form5rc extends InsnFormat {

	/** {@code non-null;} unique instance of this class */
	public static final InsnFormat THE_ONE = new Form5rc();

	/**
	 * Constructs an instance. This class is not publicly instantiable. Use
	 * {@link #THE_ONE}.
	 */
	private Form5rc() {
		// This space intentionally left blank.
	}

	/** {@inheritDoc} */
	@Override
	public String insnArgString(DalvInsn insn) {
		return regRangeString(insn.getRegisters()) + ", " + cstString(insn);
	}

	/** {@inheritDoc} */
	@Override
	public String insnCommentString(DalvInsn insn, boolean noteIndices) {
		if (noteIndices) {
			return cstComment(insn);
		} else {
			return "";
		}
	}

	/** {@inheritDoc} */
	@Override
	public int codeSize() {
		return 5;
	}

	/** {@inheritDoc} */
	@Override
	public boolean isCompatible(DalvInsn insn) {
		if (!ALLOW_EXTENDED_OPCODES) {
			return false;
		}

		if (!(insn instanceof CstInsn)) {
			return false;
		}

		CstInsn ci = (CstInsn) insn;
		Constant cst = ci.getConstant();

		if (!((cst instanceof CstMethodRef) || (cst instanceof CstType))) {
			return false;
		}

		RegisterSpecList regs = ci.getRegisters();
		int sz = regs.size();

		return (regs.size() == 0)
				|| (isRegListSequential(regs)
						&& unsignedFitsInShort(regs.get(0).getReg()) && unsignedFitsInShort(regs
							.getWordCount()));
	}

	/** {@inheritDoc} */
	@Override
	public void writeTo(AnnotatedOutput out, DalvInsn insn) {
		RegisterSpecList regs = insn.getRegisters();
		int cpi = ((CstInsn) insn).getIndex();
		int firstReg = (regs.size() == 0) ? 0 : regs.get(0).getReg();
		int count = regs.getWordCount();

		write(out, opcodeUnit(insn), cpi, (short) count, (short) firstReg);
	}
}
